Merge pull request #9 from cuspymd/feature/dedicated-server-support-423232572268798275

Implement dedicated server support

Author: cuspymd

README.md

@@ -4,10 +4,13 @@ A Fabric mod that implements a Model Context Protocol (MCP) server, enabling AI
 
 ## Overview
 
-This mod creates an HTTP server within the Minecraft client that accepts MCP protocol requests, allowing Large Language Models to execute Minecraft commands safely and efficiently. The mod includes comprehensive safety validation to prevent destructive operations.
+This mod creates an HTTP server within the Minecraft client or dedicated server that accepts MCP protocol requests, allowing Large Language Models to execute Minecraft commands safely and efficiently. The mod includes comprehensive safety validation to prevent destructive operations.
+
+It is designed to be fully compatible with both Single-Player (Integrated Server) and Multiplayer Dedicated Servers.
 
 ## Features
 
+- **Server and Client Support**: Works on both single-player and dedicated server environments.
 - **MCP Protocol Support**: Full implementation of Model Context Protocol for AI interaction
 - **Safety Validation**: Comprehensive command filtering and validation system
 - **Asynchronous Execution**: Non-blocking command execution to maintain game performance
@@ -34,9 +37,17 @@ This mod creates an HTTP server within the Minecraft client that accepts MCP pro
 
 The MCP server starts automatically when you launch Minecraft with the mod installed. By default, it runs on `localhost:8080`.
 
+### Server vs Client Modes
+
+The mod detects if it is running in a Client (Single Player) or a Dedicated Server environment:
+- **Client Mode**: Full feature support, including the `take_screenshot` tool, which uses the local game window.
+- **Dedicated Server Mode**: Has access to tools like `execute_commands`, `get_player_info`, and `get_blocks_in_area`, enabling full AI manipulation of the world without rendering. The `take_screenshot` tool is disabled in server mode since there is no rendering context. Note that `get_player_info` currently selects the first online player on the server to report its location.
+
+If playing Single Player, the integrated server logic runs through the client-side MCP.
+
 ### Configuration
 
-The mod creates a configuration file at `config/mcp-client.json`:
+The mod creates a configuration file at `config/mcp.json`:
 
 ```json
 {
@@ -267,7 +278,7 @@ Capture a screenshot of the current Minecraft game screen. Optionally, you can s
 
 For debugging purposes, you can enable local saving of every screenshot captured by the MCP server.
 
-1. Open `config/mcp-client.json`.
+1. Open `config/mcp.json`.
 2. Set `"save_screenshots_for_debug": true` in the `client` section.
 3. Screenshots will be saved to the `mcp_debug_screenshots/` directory in your Minecraft instance folder.
 4. Files are named using the pattern: `screenshot_YYYYMMDD_HHMMSS_SSS.png`.

build.gradle

@@ -28,6 +28,12 @@ loom {
 		}
 	}
 
+	runs {
+		server {
+			source sourceSets.client
+		}
+	}
+
 }
 
 dependencies {
@@ -95,4 +101,4 @@ publishing {
 		// The repositories here will be used for publishing your artifact, not for
 		// retrieving dependencies.
 	}
-}
+}

src/client/java/cuspymd/mcp/mod/MCPServerModClient.java

@@ -27,12 +27,18 @@ public void onInitializeClient() {
 				String transport = config.getServer().getTransport();
 
 				if ("http".equals(transport)) {
-					httpServer = new HTTPMCPServer(config);
+					httpServer = new HTTPMCPServer(config,
+						new cuspymd.mcp.mod.command.CommandExecutor(config),
+						new cuspymd.mcp.mod.utils.PlayerInfoProvider(),
+						new cuspymd.mcp.mod.utils.BlockScanner(),
+						new cuspymd.mcp.mod.utils.ScreenshotUtils(),
+						true
+					);
 					httpServer.start();
 					LOGGER.info("HTTP MCP Server started on port {}", httpServer.getPort());
 				} else {
 					// Default to stdio transport
-					ipcServer = new IPCServer(config);
+					ipcServer = new IPCServer(config, new cuspymd.mcp.mod.command.CommandExecutor(config));
 					ipcServer.start();
 					LOGGER.info("IPC Server started on port {}", ipcServer.getPort());
 				}
@@ -52,4 +58,4 @@ public void onClientShutdown() {
 			LOGGER.info("HTTP MCP Server stopped");
 		}
 	}
-}
+}

src/client/java/cuspymd/mcp/mod/command/CommandExecutor.java

@@ -19,7 +19,7 @@
 import java.util.concurrent.TimeoutException;
 import java.util.concurrent.TimeUnit;
 
-public class CommandExecutor {
+public class CommandExecutor implements cuspymd.mcp.mod.command.ICommandExecutor {
     private static final Logger LOGGER = LoggerFactory.getLogger(CommandExecutor.class);
     private static final long COMMAND_MESSAGE_WAIT_MS = 700L;
     private static final long COMMAND_MESSAGE_IDLE_MS = 120L;

src/client/java/cuspymd/mcp/mod/utils/BlockScanner.java

@@ -10,10 +10,15 @@
 import java.util.ArrayList;
 import java.util.List;
 
-public class BlockScanner {
+public class BlockScanner implements cuspymd.mcp.mod.utils.IBlockScanner {
     private static final Logger LOGGER = LoggerFactory.getLogger(BlockScanner.class);
 
-    public static JsonObject scanBlocksInArea(JsonObject fromPos, JsonObject toPos, int maxAreaSize) {
+    @Override
+    public JsonObject scanBlocksInArea(JsonObject fromPos, JsonObject toPos, int maxAreaSize) {
+        return scanBlocksInAreaStatic(fromPos, toPos, maxAreaSize);
+    }
+
+    public static JsonObject scanBlocksInAreaStatic(JsonObject fromPos, JsonObject toPos, int maxAreaSize) {
         try {
             MinecraftClient client = MinecraftClient.getInstance();
             if (client.world == null) {
@@ -71,7 +76,7 @@ public static JsonObject scanBlocksInArea(JsonObject fromPos, JsonObject toPos,
             result.add("area", areaInfo);
 
             // Scan blocks
-            List<JsonObject> blockList = new ArrayList<>();
+            List<BlockCompressor.BlockData> blockList = new ArrayList<>();
             int totalBlocks = 0;
 
             for (int x = minX; x <= maxX; x++) {
@@ -85,13 +90,7 @@ public static JsonObject scanBlocksInArea(JsonObject fromPos, JsonObject toPos,
                             continue;
                         }
 
-                        JsonObject blockInfo = new JsonObject();
-                        blockInfo.addProperty("x", x);
-                        blockInfo.addProperty("y", y);
-                        blockInfo.addProperty("z", z);
-                        blockInfo.addProperty("type", blockState.getBlock().toString());
-                        
-                        blockList.add(blockInfo);
+                        blockList.add(new BlockCompressor.BlockData(x, y, z, net.minecraft.registry.Registries.BLOCK.getId(blockState.getBlock()).toString()));
                         totalBlocks++;
                     }
                 }

src/client/java/cuspymd/mcp/mod/utils/PlayerInfoProvider.java

@@ -6,9 +6,14 @@
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
 
-public class PlayerInfoProvider {
+public class PlayerInfoProvider implements cuspymd.mcp.mod.utils.IPlayerInfoProvider {
 
-    public static JsonObject getPlayerInfo() {
+    @Override
+    public JsonObject getPlayerInfo() {
+        return getPlayerInfoStatic();
+    }
+
+    public static JsonObject getPlayerInfoStatic() {
         MinecraftClient client = MinecraftClient.getInstance();
         ClientPlayerEntity player = client.player;
         World world = client.world;

src/client/java/cuspymd/mcp/mod/utils/ScreenshotUtils.java

@@ -21,10 +21,15 @@
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 
-public class ScreenshotUtils {
+public class ScreenshotUtils implements cuspymd.mcp.mod.utils.IScreenshotUtils {
     private static final Logger LOGGER = LoggerFactory.getLogger(ScreenshotUtils.class);
     static final List<DeferredTask> pendingDeferredTasks = Collections.synchronizedList(new ArrayList<>());
 
+    @Override
+    public CompletableFuture<String> takeScreenshot(JsonObject params) {
+        return takeScreenshotStatic(params);
+    }
+
     static class DeferredTask {
         Runnable runnable;
         int remainingTicks;
@@ -43,7 +48,7 @@ static class DeferredTask {
      * @param params JsonObject containing optional x, y, z, yaw, pitch
      * @return A CompletableFuture that completes with the Base64 encoded PNG image data
      */
-    public static CompletableFuture<String> takeScreenshot(JsonObject params) {
+    public static CompletableFuture<String> takeScreenshotStatic(JsonObject params) {
         MinecraftClient client = MinecraftClient.getInstance();
         CompletableFuture<String> future = new CompletableFuture<>();
 

src/main/java/cuspymd/mcp/mod/MCPServerModServer.java

@@ -0,0 +1,59 @@
+package cuspymd.mcp.mod;
+
+import net.fabricmc.api.DedicatedServerModInitializer;
+import net.fabricmc.fabric.api.event.lifecycle.v1.ServerLifecycleEvents;
+import cuspymd.mcp.mod.bridge.HTTPMCPServer;
+import cuspymd.mcp.mod.bridge.IPCServer;
+import cuspymd.mcp.mod.config.MCPConfig;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class MCPServerModServer implements DedicatedServerModInitializer {
+    public static final Logger LOGGER = LoggerFactory.getLogger("mcp-server-mod");
+    private HTTPMCPServer httpServer;
+    private IPCServer ipcServer;
+
+    @Override
+    public void onInitializeServer() {
+        LOGGER.info("Initializing Minecraft MCP Dedicated Server");
+
+        ServerLifecycleEvents.SERVER_STARTED.register(server -> {
+            try {
+                MCPConfig config = MCPConfig.load();
+                if (config.getServer().isAutoStart()) {
+                    String transport = config.getServer().getTransport();
+
+                    if ("http".equals(transport)) {
+                        httpServer = new HTTPMCPServer(config,
+                            new cuspymd.mcp.mod.server.tools.ServerCommandExecutor(config, server),
+                            new cuspymd.mcp.mod.server.tools.ServerPlayerInfoProvider(server),
+                            new cuspymd.mcp.mod.server.tools.ServerBlockScanner(server),
+                            new cuspymd.mcp.mod.server.tools.ServerScreenshotUtils(),
+                            false
+                        );
+                        httpServer.start();
+                        LOGGER.info("HTTP MCP Server started on port {}", httpServer.getPort());
+                    } else {
+                        // Default to stdio transport
+                        ipcServer = new IPCServer(config, new cuspymd.mcp.mod.server.tools.ServerCommandExecutor(config, server));
+                        ipcServer.start();
+                        LOGGER.info("IPC Server started on port {}", ipcServer.getPort());
+                    }
+                }
+            } catch (Exception e) {
+                LOGGER.error("Failed to start MCP Server", e);
+            }
+        });
+
+        ServerLifecycleEvents.SERVER_STOPPING.register(server -> {
+            if (ipcServer != null) {
+                ipcServer.stop();
+                LOGGER.info("IPC Server stopped");
+            }
+            if (httpServer != null) {
+                httpServer.stop();
+                LOGGER.info("HTTP MCP Server stopped");
+            }
+        });
+    }
+}

…uspymd/mcp/mod/bridge/HTTPMCPServer.java …uspymd/mcp/mod/bridge/HTTPMCPServer.javasrc/client/java/cuspymd/mcp/mod/bridge/HTTPMCPServer.java renamed to src/main/java/cuspymd/mcp/mod/bridge/HTTPMCPServer.java src/client/java/cuspymd/mcp/mod/bridge/HTTPMCPServer.java renamed to src/main/java/cuspymd/mcp/mod/bridge/HTTPMCPServer.java

@@ -6,12 +6,12 @@
 import com.sun.net.httpserver.HttpExchange;
 import com.sun.net.httpserver.HttpHandler;
 import com.sun.net.httpserver.HttpServer;
-import cuspymd.mcp.mod.command.CommandExecutor;
+import cuspymd.mcp.mod.command.ICommandExecutor;
 import cuspymd.mcp.mod.config.MCPConfig;
 import cuspymd.mcp.mod.server.MCPProtocol;
-import cuspymd.mcp.mod.utils.PlayerInfoProvider;
-import cuspymd.mcp.mod.utils.BlockScanner;
-import cuspymd.mcp.mod.utils.ScreenshotUtils;
+import cuspymd.mcp.mod.utils.IPlayerInfoProvider;
+import cuspymd.mcp.mod.utils.IBlockScanner;
+import cuspymd.mcp.mod.utils.IScreenshotUtils;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -31,14 +31,33 @@ public class HTTPMCPServer {
     private static final Gson GSON = new Gson();
 
     private final MCPConfig config;
-    private final CommandExecutor commandExecutor;
+    private final ICommandExecutor commandExecutor;
+    private final IPlayerInfoProvider playerInfoProvider;
+    private final IBlockScanner blockScanner;
+    private final IScreenshotUtils screenshotUtils;
+    private final boolean screenshotToolEnabled;
     private final AtomicBoolean running = new AtomicBoolean(false);
     private HttpServer httpServer;
     private ExecutorService executor;
 
-    public HTTPMCPServer(MCPConfig config) {
+    public HTTPMCPServer(MCPConfig config, ICommandExecutor commandExecutor, IPlayerInfoProvider playerInfoProvider, IBlockScanner blockScanner, IScreenshotUtils screenshotUtils) {
+        this(config, commandExecutor, playerInfoProvider, blockScanner, screenshotUtils, true);
+    }
+
+    public HTTPMCPServer(
+        MCPConfig config,
+        ICommandExecutor commandExecutor,
+        IPlayerInfoProvider playerInfoProvider,
+        IBlockScanner blockScanner,
+        IScreenshotUtils screenshotUtils,
+        boolean screenshotToolEnabled
+    ) {
         this.config = config;
-        this.commandExecutor = new CommandExecutor(config);
+        this.commandExecutor = commandExecutor;
+        this.playerInfoProvider = playerInfoProvider;
+        this.blockScanner = blockScanner;
+        this.screenshotUtils = screenshotUtils;
+        this.screenshotToolEnabled = screenshotToolEnabled;
     }
 
     public void start() throws IOException {
@@ -275,7 +294,7 @@ private JsonObject handlePing() {
 
     private JsonObject handleToolsList() {
         JsonObject response = new JsonObject();
-        response.add("tools", MCPProtocol.getToolsListResponse(config));
+        response.add("tools", MCPProtocol.getToolsListResponse(config, screenshotToolEnabled));
         return response;
     }
 
@@ -295,6 +314,9 @@ private JsonObject handleToolsCall(JsonObject params) {
                     return handleGetBlocksInArea(arguments);
                 }
                 case "take_screenshot" -> {
+                    if (!screenshotToolEnabled) {
+                        return MCPProtocol.createErrorResponse("Tool not available in dedicated server mode", null);
+                    }
                     return handleTakeScreenshot(arguments);
                 }
                 case null, default -> {
@@ -315,7 +337,7 @@ private JsonObject handleToolsCall(JsonObject params) {
 
     private JsonObject handleGetPlayerInfo() {
         try {
-            JsonObject playerInfo = PlayerInfoProvider.getPlayerInfo();
+            JsonObject playerInfo = playerInfoProvider.getPlayerInfo();
 
             // Check if there was an error getting player info
             if (playerInfo.has("error")) {
@@ -347,7 +369,7 @@ private JsonObject handleGetBlocksInArea(JsonObject arguments) {
             }
 
             int maxAreaSize = config.getServer().getMaxAreaSize();
-            JsonObject result = BlockScanner.scanBlocksInArea(fromPos, toPos, maxAreaSize);
+            JsonObject result = blockScanner.scanBlocksInArea(fromPos, toPos, maxAreaSize);
 
             // Check if there was an error scanning blocks
             if (result.has("error")) {
@@ -405,7 +427,7 @@ JsonObject awaitScreenshotResult(CompletableFuture<String> future) {
     }
 
     CompletableFuture<String> takeScreenshotAsync(JsonObject params) {
-        return ScreenshotUtils.takeScreenshot(params);
+        return screenshotUtils.takeScreenshot(params);
     }
 
     private JsonObject createSuccessResponse(JsonObject result, Integer requestId) {

…va/cuspymd/mcp/mod/bridge/IPCServer.java …va/cuspymd/mcp/mod/bridge/IPCServer.javasrc/client/java/cuspymd/mcp/mod/bridge/IPCServer.java renamed to src/main/java/cuspymd/mcp/mod/bridge/IPCServer.java src/client/java/cuspymd/mcp/mod/bridge/IPCServer.java renamed to src/main/java/cuspymd/mcp/mod/bridge/IPCServer.java

@@ -3,7 +3,7 @@
 import com.google.gson.Gson;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
-import cuspymd.mcp.mod.command.CommandExecutor;
+import cuspymd.mcp.mod.command.ICommandExecutor;
 import cuspymd.mcp.mod.config.MCPConfig;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -20,13 +20,13 @@ public class IPCServer {
     private static final Gson GSON = new Gson();
     private static final int IPC_PORT = 25565; // Default port for IPC
 
-    private final CommandExecutor commandExecutor;
+    private final ICommandExecutor commandExecutor;
     private final AtomicBoolean running = new AtomicBoolean(false);
     private ServerSocket serverSocket;
     private ExecutorService executor;
 
-    public IPCServer(MCPConfig config) {
-        this.commandExecutor = new CommandExecutor(config);
+    public IPCServer(MCPConfig config, ICommandExecutor commandExecutor) {
+        this.commandExecutor = commandExecutor;
     }
 
     public void start() throws IOException {